Multiple bonds between transition metals and main-group elements, 163 Nitrogen-donor adducts of organorhenium( VII) oxides: Structural and catalytic aspects

Article abstract of DOI:10.1016/S0022-328X(96)06919-7

N-base adducts of methyltrioxorhenium(VII) (1), characterized by their structural and spectroscopic data, are compared with respect to the influence of the pK_b values of the N-bases. The crystal structure of one of these derivatives, namely the adduct of Troeger's base ((5R,11R)-(+)-2,8-dimethyl-6H,12H-5,11-methanodibenzo[b,f]-[1,5]diazocine) with compound 1 (2a) is reported. The cell constants are as follows: a = 1281.6(2)pm, b = 833.9(1)pm, c = 1705.5(2)pm, β = 106.09(1)°, V = 1751.2(4)×10⁶ pm³. Derivative 2a exhibits the longest Re(VII)-N bond distance known to date. Furthermore, 2a is the first adduct of Troeger's base whose structure has been examined by X-ray crystallography. Epoxidation and sulfoxidation catalysis with N-base adducts of 1 is described, the influence of the Re-N bond strength on the catalytic processes is discussed.